Structural characterization, thermoluminescence studies and kinetic parameters of SrSO4:Eu nanophosphors under X-ray and gamma excitations

Autor: S. Jayasudha, Thayal Singh Elias, V.M. Anandakumar, K. Madhukumar, C.M.K. Nair, Resmi G. Nair
Rok vydání: 2016
Předmět:
Zdroj: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 155:21-27
ISSN: 1386-1425
DOI: 10.1016/j.saa.2015.10.029
Popis: Nanostructured SrSO4:Eu phosphors with high thermoluminescence (TL) emission temperatures have been synthesized through a controlled chemical precipitation method. Structural analysis and TL studies under both γ-ray and X-ray excitations were done. The phosphors were characterized using Powder X-ray diffraction, X-ray photoelectron spectroscopy, SEM, TEM, thermogravimetry, UV-VIS and photoluminescence studies. The average crystallite size estimated using PXRD data is found to be around 40nm. XPS and PL studies reveal that Eu(2+) ions are the luminescence emission centres in the phosphor. The phosphor is found to be highly TL sensitive to both γ-rays and X-rays with very high emission temperature which is not reported so far. The emission behaviour is suitable for environmental radiation dosimetry applications. The TL glow curve shows well-defined isolated high temperature emission peak at 312°C under 2Gy γ-excitation and 284°C for low energy diagnostic X-ray irradiation and 271°C for high energy therapeutic X-rays. Chen's peak shape method is applied to obtain the kinetic parameters behind the TL emission. The TL mechanism is found to follow second order kinetics, suggesting the probability of re-trapping of charge carriers.
Databáze: OpenAIRE
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